""Also, there is a theory that some racial groups have prowess in certain sports.
E.g. NW Africans seem to excel in marathons.
Racist?""

No, not racist. Just inaccurate and meaningless.

If you ever took the trouble to do your homework you would be aware that it is not being a North West African which gives them this extra ability, but being born and living at high altitude.

Virtually all of this group of marathon runners hail from territory in excess of 7000 feet above sea level.

But then, you admit to lacking the stamina to read posts on this forum, if they are more than a few sentences long, which possibly explains why you get your opinions pre-digested from self styled experts.

Don T.